1. Field of the Invention
The present invention relates to PSIP (program and system information protocol) of ATSC (advanced television systems committee) prescribed as a digital TV standard, and more particularly, to a virtual channel table (VCT) data structure, transport stream discrimination method, and digital broadcast receiver, by which streams transferred within a channel can be identified with VCT only by extending a VCT syntax.
2. Discussion of the Related Art
Generally, Korea, U.S.A., and Canada have adopted ATSC (advanced television systems committee) as a digital broadcast standard. The ATSC defines PSIP (program and system information protocol) for searching a specific channel and audio and video transferred over the channel as well as audio/video encoding and decoding standards. And, the PSIP, which is regulated by a group of U.S. ATSC, is a protocol for transferring supplementary information containing information essentially necessary for viewing a digital TV.
Namely, EPG (electronic program guide) and SI (system information) are grouped into PSIP. The PSIP, which is a standard of ATSC for terrestrial and cable digital broadcasting, is defined to provide various kinds of information about a program in a manner of parsing messages encoded by MPEG-2 (moving picture experts group: ISO/IEC 1318-1 system). In other words, the PSIP standard is based on MPEG-2 (ISO/IEC 13818-1) and all tables defined in the PSIP follow private section syntaxes.
The PSIP consists of various tables to enable transmission/reception of A/V data according to MPEG-2 video and AC-3 audio formats and transmission of information of channels of broadcasting stations, information of programs of each of the channels, and the like. And, the PSIP can support a navigation function of providing an A/V service of specific broadcasting by a channel selection and a supplementary function of providing EPG for a broadcast program, i.e., a broadcast guide service.
FIG. 1 is a structural diagram of PSIP according to a related art.
Referring to FIG. 1, channel information for channel selection and information of a packet identifier number (PID) for A/V reception and the like are transferred via virtual channel table (VCT) and EPG informations of broadcast programs of respective channels are transferred via event information table (EIT). Namely, by parsing the VCT, it is able to know audio and video packet identifiers (PID) of the broadcast program carried over the channel together with a channel name, a channel number, and the like. Besides, in the PSIP, there exist a system time table (STT) for time information and a rating region table (RRT) for transferring information for a region, a consultation organ, and the like for a program rate. And, in the PSIP, there exist an extended text table (ETT) for supplementary explanation of a channel and a broadcast program, a master guide table (MGT) for management of versions and PIDs of the respective tables, and the like. Theses tables are transferred by a data structure called a section. Namely, each of the tables includes a basic unit called the section. And, at least one or more sections are combined to configure one table.